In panel display technology field presently, liquid crystal display devices are dominant due to their advantages of small volume, low power consumption and no irradiation. According to different types of light sources being adopted (internal light source, and external light source), liquid crystal display devices may be classified into transmissive, reflective and transflective types.
Among them, transflective liquid crystal display devices can both utilize light from internal backlight source and light from external environment while displaying pictures, have good visibility of pictures as transmissive display devices and low energy consumption as reflective display devices. It satisfies the requirements for both sufficient external light (e.g., outdoors) and insufficient external light (e.g., indoors), and thus are widely used in portable mobile electronic equipments.
Typically, each pixel unit of a transflective liquid crystal display device comprises a transmissive region and a reflective region, and a reflection structure for reflecting light is provided in the reflective region. Light emitted from the backlight source passes and exits the transmissive region. After entering the liquid crystal display device, the external environment light is reflected by the reflection structure in the reflective region to exit the screen, thereby enabling the user to see the pictures displayed on the screen. However, light emerged from the transmissive region passes the liquid crystal molecular layer only once, while light emerged from the reflective region passes the liquid crystal molecular layer twice. Given the same thickness of liquid crystal layer, the optical path of reflective region is twice the optical path of transmissive region, which results in an optical path difference, and leads to unmatched phase delays of light emerging from transmissive region and reflective region, thereby severely affecting the display effect.
A known method for addressing the above problem is to adopt a double cell thickness structure in which the thickness of liquid crystal layer in the transmissive region is adjusted to be two times the thickness of liquid crystal layer in the reflective region, thereby enabling the phase delays for transmissive region and reflective region to be consistent. However, in order to form a double cell thickness structure, it is required to fabricate an organic insulating layer in the reflective region to lift up liquid crystal layer in the region, moreover, the subsequent rubbing process performed on the alignment layer become very difficult due to the uneven substrate surface, which leads to processing difficulty in manufacturing transflective liquid crystal display devices.